<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>Document</title>
  <style>

  *{
   margin:0;
   padding:0
  }

  </style>
</head>

<body>
 <ul> 
   <!-- <li>1</li> -->
   <li>2</li>
   <li class="li">3</li>
   <li>4</li>
   <li>5</li>
 </ul>

</body>

  <script>
    //nodeType =1 是元素节点 nodeType =8 是注释  nodeType =3 文本
    var  ul = document.querySelector('ul');
    console.log(ul.childNodes);
  </script>
</html>